The present invention relates to a medium-voltage electric distribution cubicle designed to be fitted between two parts of an electric circuit so as to perform at least the functions respectively of current flow between the parts, of current interruption between the parts, of circuit disconnection, and of earthing of one of the above-mentioned parts.
In known electric distribution cubicles, vacuum cartridges are used to perform the switch and circuit breaker functions whereas air- or gas-insulation devices are used to perform the disconnection or earthing functions.
These functions can be combined in different ways to achieve functional units performing at the same time current flow, current interruption, disconnection and earthing functions.
A functional unit is thus known composed of a three-position switchgear device respectively performing the switch, disconnecting switch and earthing switch functions, or a functional unit composed of a switch disconnector combined with an earthing switch, or a functional unit composed of a two-position disconnecting switch comprising earthing combined with a switch or a circuit breaker. And a functional unit is also known for example formed by a combination of three devices respectively performing the disconnecting switch, earthing switch and switch functions.
The present invention proposes a medium-voltage electric distribution cubicle enabling the current flow, current interruption, disconnection, and earthing functions to be respectively performed, said cubicle being of simple design while at the same time performing disconnection providing enhanced safety when an operation is performed on the power system.
The invention also procures optimization of the dimensioning of the live components.